diff --git a/source/_integrations/sms.markdown b/source/_integrations/sms.markdown
index 7791e5b3eec..dfd8bf976ed 100644
--- a/source/_integrations/sms.markdown
+++ b/source/_integrations/sms.markdown
@@ -13,6 +13,7 @@ ha_codeowners:
 The `sms` integration allows having a local execution SMS notification via [Gammu](https://wammu.eu/gammu/). This is ideal when the internet is offline or when the power goes out.
 
 This integration provides the following platforms:
+
 - Notify
 
 ## Configuration
@@ -32,6 +33,7 @@ notify:
     name: sms_person2
     recipient: PHONE_NUMBER
 ```
+
 {% configuration %}
 device:
   description: The gsm modem device.
@@ -41,21 +43,21 @@ device:
 
 To use notifications, please see the [getting started with automation page](/getting-started/automation/).
 
-If the integration is used in HassOS then version [3.6](https://github.com/home-assistant/hassos/releases/tag/3.6) or higher is required.
+If the integration is used with the Home Assistant Operating System, then version [3.6](https://github.com/home-assistant/hassos/releases/tag/3.6) or higher is required.
 
-For installations not running on Hass.io or Docker, you must install `gammu-dev` package:
+For installations not running on Home Assistant or Home Assistant Core using Docker, you must install `gammu-dev` package:
 
 ```bash
 sudo apt-get install libgammu-dev
 ```
 
-Before running for the first time, check that the modem is recognized by the system by running:
+Before running for the first time, check that the system recognizes the modem by running:
 
 ```bash
 ls -l /dev/*USB*
 ```
 
-Note: In Hass.io you need to install the SSH add-on.
+Note: When running Home Assistant, you need to install the SSH add-on.
 
 ## Required Hardware
 
@@ -65,22 +67,50 @@ You will need a USB GSM stick modem.
 
 - [Huawei E3372-510](https://www.amazon.com/gp/product/B01N6P3HI2/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1)(
 Need to unlock it using [this guide](http://blog.asiantuntijakaveri.fi/2015/07/convert-huawei-e3372h-153-from.html))
+- [Huawei E3531](https://www.amazon.com/Modem-Huawei-Unlocked-Caribbean-Desbloqueado/dp/B011YZZ6Q2/ref=sr_1_1?keywords=Huawei+E3531&qid=1581447800&sr=8-1)
 
 [List of modems that may work](https://www.asus.com/event/networks_3G4G_support/)
 
-### Note about Raspberry PI 4
+### Huawei modems on Raspberry Pi (and similar) devices
 
-On Raspberry PI 4, you need a udev rule in the config USB stick, for the [Huawei E3372-510 stick](https://www.amazon.com/gp/product/B01N6P3HI2/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) for it to be recognized.
+For some unknown reason, the rule that converts these modems from storage devices into serial devices does not run automatically. To work around this problem, follow the procedure to create `udev` rule on a configuration USB stick for the device to switch to serial mode.
+
+1. Run `lsusb`, its output looks like this:
+
+```bash
+bus 000 device 001: ID 1FFF:342a
+bus 001 device 005: ID 12d1:15ca   <-------- Huawei is usually 12d1
+bus 000 device 002: ID 2354:5352
+bus 000 device 002: ID 1232:15ca
+```
+
+Identify the brand for your GSM modem, copy the `brand_Id` and `product_id` (In this case `brand_id = 12d1` and `product_Id = 15ca`)
 
 Set this content in file `udev\10-gsm-modem.rules` in the configuration USB:
+(Replace `brand_Id` and `product_id` for the numbers reported by `lsusb`)
 
-```txt
+```bash
+ACTION=="add" \
+, ATTRS{idVendor}=="brand_Id" \
+, ATTRS{idProduct}=="product_Id" \
+, RUN+="/sbin/usb_modeswitch -X -v brand_Id -p product_Id"
+```
+
+Here is a sample configuration file:
+
+```bash
 ACTION=="add" \
 , ATTRS{idVendor}=="12d1" \
-, ATTRS{idProduct}=="14fe" \
-, RUN+="/sbin/usb_modeswitch -X -v 12d1 -p 14fe"
+, ATTRS{idProduct}=="15ca" \
+, RUN+="/sbin/usb_modeswitch -X -v 12d1 -p 15ca"
 ```
 
+Plug the USB stick, reboot the device, run `lsusb` again.
+The resulting product id now should be different and the brand id should be the same.
+And `ls -l /dev/*USB*` should now report your device.
+
+If the device is still not recognized, remove the parameter -X from the usb_modesiwtch command and reboot again.
+
 ## More details:
 
 - [Original thread discussion](https://community.home-assistant.io/t/send-sms-with-usb-gsm-modem-when-alarm-triggered/28942/38)